Proposed wilderness protections long sought by U.S. Rep. Diana DeGette for hundreds of thousands of acres of land in Colorado cleared the House of Representatives Wednesday as part of the largest wilderness measure passed by that chamber in more than a decade.

The Protecting America’s Wilderness Act cleared the Democrat-controlled House by a 231-183 vote. It proposes to protect more than 660,000 acres of land in Colorado, including in Mesa County, as wilderness, the highest level of permanent protection available. That would make them forever off-limits to activities like mining, oil and gas development, and road-building and motorized travel.

Altogether, the measure would provide wilderness protections to nearly 1.4 million acres of land in Colorado, California and Washington state, and add some 1,000 miles of rivers to the National Wild and Scenic Rivers System.

DeGette, D-Denver, has been working for more than two decades to protect hundreds of thousands of mostly lower- and mid-elevation lands in Colorado as wilderness. The bill passed Wednesday includes 25,624 acres in Demaree Canyon northwest of Grand Junction, 28,279 acres in the Little Bookcliffs area north of Palisade, some 18,000 acres in Bangs Canyon near Grand Junction, and some 26,000 acres known as The Palisade and nearly 20,000 acres in Unaweep Canyon, both southwest of Grand Junction.

After what was then DeGette’s Colorado Wilderness Act cleared the House Natural Resources Committee in November, she agreed to incorporate several public lands bills from California and Washington into it.

“The areas that will be protected under this bill are some of the most beautiful and pristine landscapes that our country has to offer. And by officially designating them as wilderness, as this bill does, we will finally be providing them the permanent protection they deserve,” DeGette said.

Her proposal in Colorado has faced opposition from Mesa, Garfield, Montezuma and Dolores counties, however, and also from U.S. Rep. Scott Tipton, R-Cortez, whose district contains many of the lands affected.

Tipton on Wednesday was able to get the bill amended to require a study of the impact of wilderness designations on Department of Defense readiness in the West. His concern pertains to the High-Altitude Army National Guard Aviation Training Site in Eagle County, which serves as a base for helicopter training in area mountains. Tipton says that the wilderness bill passed Wednesday would establish five wilderness or potential wilderness areas within the facility’s training area.

“While there still remain several flaws in this legislation, I’m glad to have made a small improvement that will help ensure Congress fully understands the impact that these land designations may have on military readiness in the future,” Tipton said in a news release.

Also Wednesday, DeGette got House approval to amend the bill’s Colorado provisions to add four more areas that would be protected as wilderness. These include the Diamond Breaks area in far-northwestern Colorado, and Papoose Canyon and North Ponderosa Gorge and South Ponderosa Gorge in southwest Colorado.

The wilderness package likely faces difficulty getting through the Republican-controlled Senate. DeGette is working with senators to try to get it included in any land-protection package the Senate may consider this year.

"The decision to permanently protect more than 600,000 acres of wilderness is excellent news for the state, especially while so many of Colorado's national parks are under threat of nearby oil and gas drilling,” Tracy Coppola of the National Parks Conservation Association said in a prepared statement Wednesday. “Having nearby land designated as wilderness and protected is important for the health of our national parks' ecosystems and we're thankful for Representative DeGette's leadership in making this happen."